The present invention relates to a lifter for use with different kinds of containers having different heights for moving the container upward and downward with a stroke corresponding to the height of the container in filling the container with a liquid in an amount corresponding to the height of the container.
As disclosed in JP-A No. 5-147695 (EPC 0 545 483), conventional lifters of the type mentioned are adapted for use in a liquid filling apparatus comprising a container conveyor provided on a bed, and a filling nozzle disposed above a path of transport of containers. The known lifter comprises a container pushing-up vertical lift rod disposed below the filling nozzle and extending through the bed, a container pushing-down vertical lift rod extending through the bed at one side of the lift rod, a horizontal connecting bar positioned below the bed and interconnecting the two lift rods, a container support fixed to the upper end of the container pushing-up lift rod, a container holder so disposed as to be movable upward and downward along the container pushing-down lift rod, a chuck for setting the container holder in position above the bed relative to the container pushing-down lift rod adjustably in position so as to determine the spacing between the container support and the container holder in corresponding relation with the height of the container, and a release mechanism for the chuck.
Since the chuck and the release mechanism therefor are provided above the bed in the vicinity of the filling nozzle, the lift described has the problem that the construction of the lifter is complex around the filling nozzle above the bed.
An object of the present invention is to provide a liquid metering and filling lifter for use with containers which has a simplified construction around the filling nozzle above the bed.
The present invention provides a liquid metering and filling lifter for use with different kinds of containers having different heights for moving the container upward and downward with a stroke corresponding to the height of the container in filling a liquid into the container, the lifter comprising a container pushing-up vertical lift rod disposed below a filling nozzle above a bed and extending through the bed, the lift rod having a container support fixed to an upper end thereof; a container pushing-down vertical lift rod extending through the bed at one side of the lift rod and having a container holder fixed to an upper end thereof; and coupling means disposed below the bed for coupling the two lift rods to make the lift rods movable upward or downward together and uncoupling the lift rods to make the lift rods movable upward or downward individually.
With the lifter of the present invention, the two lift rods are coupled or uncoupled as required by coupling means below the bed, and the components provided above the bed are limited only to the portions of the two lift rods projecting upward beyond the bed, the container support and the container holder. In fact, there are none of coupling means and the like above the bed. Accordingly, the lifter is simple in its construction in the vicinity of the filling nozzle above the bed, and the parts around the filling nozzle can be cleaned very effectively to ensure sanitation and the ease of maintenance.
The coupling means comprises a connector interconnecting the two lift rods, and the connector is fixed to one of the lift rods and disengageably engaged with the other lift rod shiftably longitudinally thereof. It is then possible to alter the stroking position of the two lift rods due to a change in the height of containers, merely by shifting one of the two lift rods longitudinally thereof relative to the connector before coupling.
The coupling means has a connector fixed to the container pushing-up lift rod, and the connector is provided with a vertical rod bore having the container pushing-down lift rod slidably inserted therethrough, the container pushing-down lift rod having a plurality of engaging bores radially extending therethrough and arranged at intervals corresponding to the differences between the containers in height, a connecting rod being movable into or out of the connector radially of the rod bore and selectively fittable into one of the engaging bores when moved into the connector. It is then possible to readily alter the stroking position of the two lift rods due to a change in the height of containers, merely by fitting the connecting rod into one of the engaging bores. Additionally, the container holder can then be set in position correctly relative to the container pushing-down lift rod with respect to the direction of rotation.
When the liquid metering and filling lifter further comprises lock means for releasably locking the container pushing-down lift rod at a bottom dead center of the lift stroke thereof, a piston rod can be fitted into required one of the engaging bores by the operation of a fluid pressure cylinder, after moving the container pushing-up lift rod upward or downward along with the connector, with the container pushing-down lift rod locked by the lock means, halting the connector at a required position and positioning the piston rod as opposed to the required engaging bore. Accordingly, the piston rod can be very readily fitted into the required engaging bore which is selected with extreme ease.
The container pushing-down lift rod is provided in an outer surface thereof with a horizontal engaging groove, and the lock means has an engaging member movable into or out of the engaging groove when the container pushing-down lift rod is positioned at the bottom dead center of the lift stroke thereof. The lift rod can then be locked easily by the lock means.
A vertical endless belt is disposed along a path of upward and downward movement of the connector, with a one-side straight moving portion of the belt opposed to the path, the connector being fixed to the straight moving portion, and the endless belt is driven by a motor which is variable in the amount of rotation. The two lift rods are then movable upward and downward with a variable stroke by the smooth operation of belt drive.